Euphydryas Aurinia Research Articles

Large, but Dispersal-Limited Populations of the Marsh Fritillary Euphydryas aurinia Persist on Abandoned Military Training Areas Three Decades After the End of the Cold War.

Military training areas can host important biodiversity, due to the preservation of diverse, nutrient-poor historical cultural landscapes and an insect-friendly disturbance regime. In Europe, many training areas were abandoned after the end of the cold war in 1991 and the withdrawal of the Allied and Soviet forces. Many of these are now protected areas, and current management strategies vary from rewilding to active habitat management such as grazing or mowing. In a capture-release-recapture approach, marking 2418 individuals, we assessed the population size and movement patterns of the dry ecotype of the Marsh Fritillary Euphydryas aurinia Rottemburg 1775 on three former military training areas in Germany that varied in size and management (natural succession, mowing, and sheep-/goat grazing). Euphydryas aurinia is a rare and declining butterfly species listed in Annex II of the European Union Habitats Directive. Jolly-Seber models revealed a large population of ca. 19,000 individuals on the largest study site and a smaller population at a second site, whereas recapture rates were too low to predict the population size reliably at a third site. Population densities were 190-194 butterflies ha-1 at the unmanaged, large site and 56-71 butterflies ha-1 at a smaller site grazed with sheep. Thirty-nine percent of the recapture events occurred within the same 1-ha-study plot. The average minimum flight distance between the study plots was 313 m for males and 328 m for females. The maximum lifetime flight distance was 1237 m within 3 days. No dispersal was detected between study sites. Thirty years after cessation of the military use, the large former training site still held what likely is one of the largest populations of the species dry ecotype in Central Europe, including in areas where management ceased already in 1991. This suggests remarkable persistence of the species in areas without regular management, contrary to current opinion. However, regular flight distances seem not to be sufficient to connect the isolated habitat patches. It remains unknown how long the large population at the abandoned military area will persist without active habitat management. Careful, but active habitat management and restoration of habitat connectivity should thus be considered.

Landscape properties and density dependence shape the movement patterns of three threatened butterflies

ContextConservation of endangered species necessitates an in-depth understanding of their ecological requirements. Particularly in landscape ecology, the behavioural tendencies of threatened butterfly species in Gotland, a biodiversity-rich island in the Baltic Sea, become crucial.ObjectivesThe primary aim of this study was to elucidate the movement patterns of three threatened butterfly species—Euphydryas aurinia, Parnassius apollo, and Phengaris arion—in Gotland and to identify the influence of specific land characteristics on these patterns.MethodsOur study, conducted from 2017 to 2020 across 60 km2 in Gotland, involved detailed capture-mark-recapture (CMR) efforts of 29,584 captures including 16,223 unique butterflies. We investigate the departure and arrival events of butterflies, specifically focusing on the associations between movements when individuals leave or enter a hectare grid different from their previously recorded location and key landscape features: open vegetated land, ground moisture, and forest cover. We model landscape features to examine the interplay between these and butterfly movement patterns, providing insights into preferred landscape features and conservation strategies.ResultsAmong the 4821 arrivals and 5083 departures documented, the species exhibited differential responses to the evaluated habitat features. Both E. aurinia and P. apollo displayed a positive density-dependent dispersal, while P. arion’s movements were not significantly associated with any of the examined habitat features. Landscape properties like open vegetated land and ground moisture index statistically influenced the likelihood of arrival and departure.ConclusionsThe study accentuates the relationship between land cover and the behavioural tendencies of the subject butterfly species. It has broader implications for the targeted habitat management strategies that would benefit threatened butterfly populations in Gotland.

Travniški postavnež <i>Euphydryas aurinia</i> (Rottemburg, 1775) (Lepidoptera: Nymphalidae) na Ljubljanskem barju: prvi vpogled v gostiteljske rastline in pregled razširjenosti

The article presents the first insight into the host plants of the marsh fritillary (Euphydryas aurinia) in the Ljubljansko barje region and provides recent information on the species distribution in this area. There are two permanent populations of the marsh fritillary in the region, i.e. in the Draga Valley near Ig and the valley of Strajanov breg stream. The main larval host plant at Ljubljansko barje is devil's-bit scabious (Succisa pratensis). Preadult stages have also been found on willow gentian (Gentiana asclepiadea) and southern succisella (Succisella inflexa). The expanding diversity of host plants increases the likelihood of long-term survival of the species. Therefore, understanding the local ecology of the preadult stages is crucial for planning effective management strategies for the species.

Long‐distance movements, large population sizes and density‐dependent dispersal in three threatened butterfly species

Abstract This study investigates the ecology of three threatened butterfly species on a 60 km2 site in Gotland, Southeast Sweden, using mark–recapture methods from 2017 to 2020. Nearly 30,000 captures were recorded, with average lifespans of 6 days for Euphydryas aurinia (Lepidoptera: Nymphalidae) and Parnassius apollo (Lepidoptera: Papilionidae) and 2 days for Phengaris arion (Lepidoptera: Lycaenidae). Population size, density and maximum flight distances varied between species, with E. aurinia at 7.2 km, P. apollo at 6.4 km and P. arion at 2.5 km. Movement data showed the lognormal kernel fit better than gamma, negative exponential and half‐normal kernels for distance travelled per time unit across species and sexes. Generalised linear models revealed significant positive density‐dependent emigration and negative density‐dependent immigration in all three species. Despite available suitable habitats, these species face threats from limestone quarry expansions, agricultural intensification, modified forestry practices, natural succession and climate change, highlighting the need for proactive conservation and strategic habitat management.

Negative impacts of future forest succession on three threatened butterfly species

The dynamic interplay between anthropogenic activities and biodiversity conservation necessitates a nuanced understanding of habitat change, especially in contexts marked by transitions from grasslands to forested areas. This investigation utilised three threatened butterfly species—the Marsh Fritillary, Apollo, and Large Blue—as models to explore how grassland associated species respond to altered environmental conditions. The methodology encompassed extensive field surveys and statistical analyses with ecological niche modelling to determine their current and future distributions on the Island of Gotland. The species were surveyed under distinct years from 2017 to 2020 in a total of 3333 hectares in a 6000 hectare area—the Marsh Fritillary in 2017 (1232 hectares), Apollo in 2019 (2346 hectares), and Large Blue in 2020 (2256 hectares). Results revealed that the estimated current extents of suitable habitats were 49,104 hectares for the Marsh Fritillary (15.6% of the island), 45,646 hectares for Apollo (14.5%), and 33,089 hectares for Large Blue (10.5%). In general, increased forest and shrub cover and decreased heterogeneity negatively affected butterfly occupancy, but each species exhibited unique habitat preferences. The predictive modelling demonstrated that continued succession would reduce the amount of habitats predicted to be suitable and generated alarming forecasts—a twofold increase in forest and shrub cover suggests habitat declines of 41%, 47%, and 65% for the Marsh Fritillary, Apollo, and Large Blue, respectively. Given these findings, proactive measures are imperative for strategically managing these habitats to preserve landscape heterogeneity and accommodate diverse ecological needs. This study is important to conservation management providing, crucial insights amid anthropogenic and ecological changes.

Contribution to the knowledge of the butterfly fauna (Lepidoptera: Papilionoidea) of Central Slovenia

The southwestern Posavsko hills and northern Suha krajina are among the least studied areas regarding the butterfly fauna in Slovenia. To fill this knowledge gap, we selected all unpublished records of butterflies since 2014, in addition to the focused field surveys performed in the 2019–2022 period. We recorded a total of 105 butterfly species, presenting almost 60% of all species found in Slovenia. Among the species found, there are several habitat specialists of high conservation importance, e.g., Leptidea morsei, Euphydryas aurinia, Parnassius mnemosyne, Phengaris arion, Carcharodus floccifera, Lycaena dispar. Locations harbouring these species and those with the highest species richness are of great importance for preserving the diverse butterfly fauna of the region.

High hymenopteran parasitoid infestation rates in Czech populations of the Euphydryas aurinia butterfly inferred using a new molecular marker

High hymenopteran parasitoid infestation rates in Czech populations of the Euphydryas aurinia butterfly inferred using a new molecular marker

Novel grid‐based population estimates correlate with actual population sizes of the marsh fritillary (Euphydryas aurinia), while transect and larvae counts are less reliable

Abstract Established butterfly survey methods that are useful for monitoring species that are widely distributed and numerous may be less accurate for more rare species. We therefore need new monitoring approaches. We describe a plot‐based survey method, where butterflies or larvae nests are counted within 1‐ha grid cells. The aim was to compare this grid method with more traditional transect counts and evaluate both methods in relation to high‐quality capture–mark–release (CMR) population estimates (reflecting the ‘true’ population). We do this using data from a large population of the marsh fritillary butterfly in Sweden. Moreover, we followed the overall population trend from 2017 to 2021 for both adult butterflies and larvae. Results showed a higher detection probability using the grid method compared with transect counts, which for adult butterflies seem to be explained by time effort. Moreover, grid surveys of adult butterflies showed a clear significant relationship with the estimated ‘true’ population size from CMR, while transect counts did not. For larvae, both methods showed significant relationships with the estimated adult population size, but the grid method found 5.7 times more larvae. The overall population fluctuated significantly across years. In years with low densities, the transect method largely failed to detect the species. The grid method seems more reliable for detecting the marsh fritillary and for estimating its population size, and thus, tracking the population trend. We propose this novel method to be integrated into surveys and monitoring of biodiversity, especially when focusing on rare habitat specialists that are normally underrepresented in monitoring based on volunteer counts.

Caterpillar loss through grassland harvest differs between two related butterfly species of conservation concern

Abstract Temperate, semi‐natural grasslands emerged from traditional land use and are recognised for their outstanding biodiversity. However, these grasslands severely declined due to agricultural industrialisation. Accordingly, specialised species of nutrient‐poor grasslands like the closely related butterflies Nickerls Fritillary Melitaea aurelia Nickerl, 1850 and Marsh Fritillary Euphydyras aurinia (Rottemburg, 1775) (Lepidoptera: Nymphalidae) have experienced strong declines in the last century due to grassland loss and deterioration. Here, we studied for the first time the effects of the complete harvest process in grasslands from mowing until the removal of the cut vegetation on the survival of their caterpillars. To assess survival rates, we sampled larvae of both species and environmental conditions before and after the harvest process and analysed the results using generalised linear mixed‐effects models. Our study revealed that the harvest process in grasslands mown once by bar mowers resulted in substantial caterpillar loss influenced by (i) growth form of the host plants and (ii) timing of grassland harvest. Accordingly, the host plant of E. aurinia, Succisa prantensis, lost nearly half of its leaves during the harvest process, while late harvesting was especially harmful for caterpillars already commencing hibernation. Overall, E. aurinia had higher losses compared with M. aurelia, and these were most severe in late‐mown moist meadows. To increase the survival rate of E. aurinia, we recommend mowing before the beginning of hibernation using bar mowers. Complementary, or if mowing is done later, at least 20% of the meadow should be left as an untouched refuge in a spatially rotating manner.

Moderate mobility and high density in a small area: the population ecology of the marsh fritillary Euphydryas aurinia in Transylvania (Romania).

The Natura 2000 network is one of the most important tools for nature conservation in the EU. Therefore, knowledge of the ecology of the species listed on the Habitats Directive annexes is of particular relevance. One of these species is the butterfly Euphydryas aurinia. Much is already known about the ecology of this species at the European level, but information on Romania is scarce. Therefore, in a study area northwest of Cluj, the species was intensively studied in a mark-release-recapture study over its entire flight period. The investigated population harboured many individuals and had a high density. The dispersal behaviour of the individuals was somewhat more pronounced than in Mediterranean and partly also high alpine populations, but roughly comparable to other populations of the nominotypic subspecies. Overall, the ecological differences to Central and Western European populations were not very pronounced, and many of the conservation-relevant statements on this species in Central Europe should also be largely valid in Romania.

Vegetation changes at oligotrophic grasslands managed for a declining butterfly

A selection of sites occupied by the EU-protected marsh fritillary (Euphydryas aurinia) in western Czech Republic were subjected to a vegetation survey 15 years ago and again recently. In the 66 time-replicated 25 m2plots from 12 sites, representing the diversity ofE. aurinia-occupied oligotrophic grasslands in the Slavkovský les Protected Landscape Area (and covering a fifth of the currently-occupied Czech sites), we recorded quantitative representation of vascular plants and mosses. We analysed the data using multivariate ordinations, asking how the vegetation changed between the surveys, how was it affected by the conservation management applied and how it affected occupancy by the butterfly larval nests; the vegetation patterns were interpreted using Ellenberg’s plant indicator values. Between the two surveys, the overall representation of the larval host plant,Succisa pratensis, did not change; tree and herbs layers (both grasses and forbs) increased and the moss layer decreased. Across surveys, the main driver of vascular plants’ species composition was moisture, followed by soil reaction and nitrogen, whereas in mosses, nitrogen was the main factor. The main change between the surveys was the increase of nitrogen accompanied by decreased light, probably due to increase of competitively strong plants. Butterfly occupancy declined at sites with high soil moisture and increased at sites with higher soil reaction. Mowing of moist nitrogen-rich sites, but not drier nitrogen-poor sites, increased occupancy, illustrating the need for context-dependent interventions. All the evidence thus shows thatE. auriniaprefers drier, warmer and less acidic conditions within the generally moist acidic grasslands and that ongoing eutrophication represents a potential problem in the future.

Within-habitat vegetation structure and adult activity patterns of the declining butterfly Euphydryas aurinia

BackgroundEuphydryas aurinia is a declining butterfly inhabiting oligotrophic grasslands in Central and Western Europe. Despite numerous ecological studies, patterns of its adult activity have so far been rather neglected, although adult resource use contributes to resource-based understanding of insects’ habitats.AimTo relate E. aurinia adult activity patterns to within-habitat vegetation structures.Methods(1) Timed adult activity observations along a transect crossing a colony site, analysed via partial ordination methods. (2) Activity records obtained during mark-recapture, analysed via binomial regressions.ResultsBoth methods, besides influences of weather, time of day (similarities between morning and late afternoon hours), and progression of season (mate locating replaced by maintenance activities), revealed consistent association of behaviours to vegetation structures. Of the two male mate-locating behaviours, perching occurred near shrubs and woodland edges, and patrolling over centres of inhabited meadows. Female activity concentrated in nectar-rich mid-height sward near host plants. Consequently, male and female activity were partly spatially separated.Implications for conservationA habitat for E. aurinia should provide resources for all its activities in close proximity. Grasslands containing host plants should be dissected by structures such as shrubs, woodlot edges, or taller herbaceous vegetation, emphasising the importance of landscape heterogeneity for insect fauna.

New data on the distribution of the threatened Marsh Fritillary – Euphydryas aurinia (Lepidoptera: Nymphalidae) – in Romania

Euphydryas aurinia, a highly endangered species listed on the Annex II of the Habitats Directive as well as on the Annex II of the Bern Convention, has a wide distribution in the Palearctic realm. Although it is an intensively studied species, its distribution is still not enough known. In Romania, in the last century it has been reported almost exclusively from the regions inside and westwards to the Carpathian Mountains. Records from Oltenia and Wallachia are filling a gap in the known distribution of this butterfly in the southern part of Romania, while 13 new records consolidate the known range of this species in southern and eastern Transylvania. In order to assess the progress encountered, a critical reviewed checklist with the records of the Marsh Fritillary presented in a regional distribution map complete this paper.

Yearly weather variation and surface temperature drives the spatiotemporal dynamics of a threatened butterfly and its host plant

It remains unclear to what extent yearly weather variation and spatial variation in microclimate influences the outcome of interacting plant-animal species and whether responses differ between life stages. We collected data over several years on 46 ha on File Hajdar, Gotland, Sweden, and executed a complete mapping of larva nests (n= 776) and imago (n= 5,952) of the marsh fritillary butterflyEuphydryas auriniaand its host plantSuccisa pratensis. The phenology of the butterflies and the major nectar plants visited varied among years. The duration of the adult flight period decreased with increasing ambient air temperatures. The density of butterflies, host plants, and host plant leaf size increased between years with increasing precipitation in the preceding year, and decreased with increasing average ambient air temperature in the preceding year. In 2021–2022 we deployed a unmanned aerial vehicle (UAV) with a high-resolution thermal sensor to measure spatial variation in surface temperatures in the study area. We found that survival from the egg to the larva stage increased with increasing surface temperature and host plant density. Host plants and larva nests generally occupied warmer microhabitats compared to imago butterflies. The results further suggested that the relationships linking surface temperature to the densities of imago, larva, host plants, and leaf size differed qualitatively between years. In 2017, larva nests and host plant density increased with increasing surface temperatures, and butterflies showed a non-linear response with a density peak at intermediate temperatures. As a result of the extreme drought in 2018 there was a reduction in maximum leaf size, and in the densities of plants, larvae, and butterflies. Moreover, the slopes of the relationships linking the density of larvae, butterflies, and plants to temperature shifted from linear positive to negative or curvilinear. Our findings demonstrate how yearly weather variation and heterogeneous surface temperatures can drive the spatiotemporal distribution and dynamics of butterflies and their host plants. The context specificity of the responses indicated by our results makes it challenging to project how climate change will affect the dynamics of ecological communities.

The dark side of the Common Agricultural Policy

The dark side of the Common Agricultural Policy

Differences in phenology, daily timing of activity, and associations of temperature utilization with survival in three threatened butterflies

We used observational data collected during a mark-recapture study that generated a total of 7503 captures of 6108 unique individuals representing three endangered butterfly species to quantify inter-and intraindividual variation in temperature utilization and examine how activity patterns vary according to season, time of day, and ambient temperature. The Marsh Fritillary, the Apollo, and the Large Blue differed in utilized temperatures and phenology. Their daily activity patterns responded differently to temperature, in part depending on whether they were active in the beginning, middle or end of the season, in part reflecting interindividual variation and intraindividual flexibility, and in part owing to differences in ecology, morphology, and colouration. Activity temperatures varied over the season, and the Apollo and the Large Blue were primarily active at the highest available ambient temperatures (on the warmest days and during the warmest part of the day). The Marsh Fritillary was active early in the season and decreased activity during the highest temperatures. The relationship between individual lifespan and the average temperature was qualitatively different in the three species pointing to species-specific selection. Lifespan increased with an increasing range of utilized temperatures in all species, possibly reflecting that intra-individual flexibility comes with a general survival benefit.

Subsidized Common Agricultural Policy grazing jeopardizes the protection of biodiversity and Natura 2000 targeted species

AbstractIn Europe, Natura 2000 sites should protect threatened target species and networks of habitats. The management of Natura 2000 grasslands is often financed by subsidized grazing as part of the Common Agricultural Policy (CAP). We studied the extent of CAP grazing for Natura 2000 management and how this affects a butterfly target species (the marsh fritillary) and floral resources. Based on extensive capture‐mark‐release studies from 2 years in >550 ha grid cells in a 225 km2landscape in Sweden that includes 15 Natura 2000 sites, we compared marsh fritillary occurrence probabilities and population densities in ungrazed and CAP‐grazed habitats. Moreover, we analyzed how nectar resources and orchids were affected by CAP grazing based on plants records from 2347 sample plots. We estimated the proportion of butterfly habitats that were CAP‐grazed within and outside Natura 2000 sites. In total, 10 453 and 4417 butterflies were marked in 2017 and 2019, respectively. The grid cell occurrence probability was 1.8 times higher and the population density was 2.3 times higher in ungrazed compared with CAP‐grazed habitats in 2017, and the corresponding numbers for 2019 were 10 and 5.3 times higher, respectively. The number of flowering plants were on average 6.9 times higher and the density of orchids was 12.3 times higher in ungrazed habitats. Roughly, 30% (130 ha) of the marsh fritillary habitat was CAP grazed, and 97% of this grazing occurred within protected areas, of which 111 ha was situated within Natura 2000 area where the marsh fritillary is the target species. Alarmingly, we show that intense yearly CAP grazing, which is the dominant management strategy in all Natura 2000 sites, has devastating consequences for the target species and other aspects of biodiversity. Less intense management, which would benefit biodiversity, requires changes in the CAP, to allow more flexible payments for habitat management objectives and conservation of target species.

Quick recovery of a threatened butterfly in well‐connected patches following an extreme drought

AbstractExtreme weather events are becoming more frequent due to climate change. We therefore need to understand how species respond to these events. In 2018, the worst drought ever recorded hit the island of Gotland in the Baltic Sea, which led to a major decline of the threatened marsh fritillary (Euphydryas aurinia) the succeeding summer.We compared yearly occupancy among 256 habitat patches between 2018 and 2020 and analysed the colonisation–extinction dynamics between 2019 and 2020 in relation to patch area, connectivity, and habitat quality. Moreover, using capture‐mark‐release data in two patch clusters differing in connectivity, we also compared population sizes before and after the drought and analysed ‘population growth rates’. We also compared yearly abundance of host plants (Succisa pratensis) over time.Results show a remarkable recovery of the marsh fritillary. Both patch occupancy in 2020 and the number of individuals in the well‐connected patch cluster were higher than before the drought. In contrast, host plants were fewer and smaller, which taken together suggest that the amount of food resources was roughly half in 2020 compared to the pre‐drought conditions. Moreover, the butterfly population in the less connected patch cluster was eight times smaller compared to the population size before the drought. Local colonisations, extinctions, and population growth rates were explained by connectivity.The ability to quickly recover after extreme droughts is promising in times of climate change. The significance of connectivity for the population dynamics during recovery highlights the importance of maintaining well‐connected patch networks.

Plant Communities in the Gradient from Raised Bog to Fen in a Near-Intact Lagg Zone in Carrownagappul Bog, Ireland

Despite the importance of lagg zones in the function and restoration of raised bog systems, there have been limited studies on their vegetation communities and environmental characteristics. Given their importance and lack of study, the vegetation in the near-intact lagg zone in the south-south-west of Carrownagappul Bog in Co. Galway was sampled along four transects in July 2020. Cluster analysis separated the vegetation, encompassing 97 species, into 5 vegetation types. There were affinities between these vegetation types and a range of Irish Vegetation Classification (IVC) bog, heath, grassland and fen communities, as well as two Habitats Directive Annex I habitat types, transition mires and alkaline fen. In addition, a population of the Annex II listed Marsh Fritillary (Euphydryas aurinia (Rottemburg, 1775)) was recorded from the area. In general, the vegetation communities reflected a gradient of increasing alkalinity, moisture and nutrient status from ombrotrophic raised bog to minerotrophic fen. The diversity of the vegetation over a small area and its near-natural conditions underscore the conservation significance of the lagg zone, and these findings accentuate the hydrological perspective that restoration of the lagg should, where possible, be a key element in raised bog restoration. The current lack of a characterisation of the lagg types found in Ireland is a barrier to developing a sound restoration and conservation management strategy.

Butterfly diversity (Lepidoptera: Papilionoidea) of Mt. Blegoš and Mt. Koprivnik (Škofjeloško hribovje, Slovenia)

An overview of the surveys of butterfly fauna of Mt. Blegoš, Mt. Koprivnik and their surroundings is provided. In 2018, 14 surveys were performed and 80 butterfly species on eight transects recorded in the process. Additional surveys in 2019 and 2020 yielded 5 additional butterfly species. Among the butterflies observed, Parnassius mnemosyne, Lycaena hippothoe, Euphydryas maturna, Euphydryas aurinia, Melitaea britomartis, Melitaea diamina, and Pyrgus alveus are identified as vulnerable species, while both Phengaris arion and Phengaris alcon are classified as endangered species in Slovenia. The latter was found on two occasions in July 2018 and July 2020 on a single locality. Eggs of P. alcon were found on the host plant Gentiana cruciata at the same locality. Despite the fact that many species characteristic of higher altitudes were observed, like Aricia artaxerxes, Pyrgus alveus, Erebia stiria and Lasiommata petropolitana, other, which had still been present a few decades ago, were not found (Parnassius apollo and Boloria pales). In this article, the problem of loss of important butterfly habitats in the region due to overgrowing, and the negative impacts of overgrazing is also highlighted.